A Simple Procedure for in Situ Immunolabeling, Embedding and Sectioning of Layers of Cultured Endothelial and Smooth Muscle Cells for both Light and Electron Microscopy

We present a simple procedure for in situ immunolabeling, embedding and sectioning of layers of cultured endothelial and smooth muscle cells for both light and electron microscopy. Endothelial and smooth muscle cells were seeded in tissue culture chambers /slides precoated with 30% (w/v) gelatin drops fixed with 0.5% glutaraldehyde. Live endothelial cell layers were labeled with an antibody against the surface membrane protein, anti-CD 13. After labeling, the cell layers were fixed and separated from the chambers/slides by lifting all of the samples with a spatula. Sections (1-2 mm) were cut, embedded and processed further for light or electron microscopy. Because of the delicate cell layers and the importance of preserving maximum integrity, labeling was performed under standard culture conditions and treated in situ during the entire procedure. Moreover, the small chamber size of the tissue culture dishes generated the additional advantages of requiring only a limited number of cells, small volumes of media, and little antibody.     

A continuous culture of pluripotent fetal hepatocytes derived from the 8-day epiblast of the pig

Summary Continuous cultures of pluripotent parenchymal hepatocytes were derived from the epiblasts of 8-day-old pig blastocysts. The cells were polygonal and had phase-contrast dark, granular cytoplasm with prominent nuclei and nucleoli. These feeder-dependent cell cultures differentiated into large, multicellular, secretory, duct-like structures or formed small canaliculi between individual cells. Alternatively, the cells accumulated droplets that stained intensely with Oil Red O, a lipid-specific stain. Alpha-fetoprotein (AFP), albumin, and β-fibrinogen mRNAs were expressed as the cells differentiated in culture. Serum-free medium that was conditioned by the cells contained transferrin, AFP, and albumin. The growth and viability of the cells were inhibited by transforming growth factor β1 (TGFβ1) at concentrations ≥1 ng/ml. The cell cultures grew slowly with doubling times of 2 to 3 d. One of the cultures, pig inner cell mass-19 (PICM-19), was passaged continuously for over 2 yr [>100 population doublings (PD)] and appears to be an infinitely self-renewing cell population. The stem cell characteristics of the epiblast-derived fetal hepatocytes indicate that the cells may be unique for investigations of liver differentiation and organogenesis.     

Phylogenetic analysis of the Cenozoic family Sieblosiidae (Insecta: Odonata), with description of new taxa from Russia, Italy and France

We describe the following Sieblosiidae: an unamed “gen. and sp. A” from the Miocene of Italy, Miostenolestes zherikhini nov. gen., nov. sp., Paraoligolestes stavropolensis nov. sp., Stenolestes fasciata nov. sp. (all from the Miocene of North Caucasus), Stenolestes (?) adygeianensis nov. sp. (Oligocene of North Caucasus), and Stenolestes cerestensis nov. sp. (Oligocene of France). The genus Sieblosia Handlirsch, 1906 is restored. A new phylogenetic analysis of the Sieblosiidae is proposed. The two taxa “gen. and sp. A” and Oligolestes fall in most inclusive positions in the same clade with the Sieblosiidae. Within the Sieblosiidae sensu stricto, the two clades (Paraoligolestes + (Parastenolestes + Stenolestes)) and (Parastenolestes + Stenolestes) are the best supported. The family Sieblosiidae seems to be restricted to the Oligocene-Miocene of Europe.     

Phylogenetic relationships of the Mesozoic paraneopteran family Archipsyllidae (Insecta: Psocodea)

The Middle Jurassic Archipsylla sinica sp. n. is the first record of the enigmatic Mesozoic family Archipsyllidae from China. This well-preserved Chinese material bears several apomorphies allowing an attribution of this family to the Psocodea. The presence of four-segmented tarsi in Archipsyllidae suggests that the reduction in number of tarsomeres occurred independently at least two times in the modern paraneopteran lineages Psocodea (“Psocoptera” + Phthiraptera) and Condylognatha (Thysanoptera + Hemiptera).     

Thioredoxin fold as homodimerization module in the putative chaperone ERp29: NMR structures of the domains and experimental model of the 51 kDa dimer.

BACKGROUND: ERp29 is a ubiquitously expressed rat endoplasmic reticulum (ER) protein conserved in mammalian species. Fold predictions suggest the presence of a thioredoxin-like domain homologous to the a domain of human protein disulfide isomerase (PDI) and a helical domain similar to the C-terminal domain of P5-like PDIs. As ERp29 lacks the double-cysteine motif essential for PDI redox activity, it is suggested to play a role in protein maturation and/or secretion related to the chaperone function of PDI. ERp29 self-associates into 51 kDa dimers and also higher oligomers. RESULTS: 3D structures of the N- and C-terminal domains determined by NMR spectroscopy confirmed the thioredoxin fold for the N-terminal domain and yielded a novel all-helical fold for the C-terminal domain. Studies of the full-length protein revealed a short, flexible linker between the two domains, homodimerization by the N-terminal domain, and the presence of interaction sites for the formation of higher molecular weight oligomers. A gadolinium-based relaxation agent is shown to present a sensitive tool for the identification of macromolecular interfaces by NMR. CONCLUSIONS: ERp29 is the first eukaryotic PDI-related protein for which the structures of all domains have been determined. Furthermore, an experimental model of the full-length protein and its association states was established. It is the first example of a protein where the thioredoxin fold was found to act as a specific homodimerization module, without covalent linkages or supporting interactions by further domains. A homodimerization module similar as in ERp29 may also be present in homodimeric human PDI.     

The use of oral contraceptive before pregnancy and breastfeeding duration: A cross-sectional study with retrospective ascertainment

Background

There is limited evidence on the use of the Snoezelen concept for maternity clients. Snoezelen, a Dutch concept, initiated in the 1970s as a leisure activity for severely disabled people, involves creating an indoor environment using controllable stimuli to enhance comfort and relaxation. These specially designed rooms expose the user to multiple sensory stimulations combining vision, touch, sounds and aromas. The aim of this study was to provide insight into breastfeeding women's experience of using a Snoezelen room during hospitalisation.

Methods

A qualitative exploratory design was chosen to reveal women's perceptions of using the Snoezelen room. Osborne Park Hospital, the study setting is the second largest public provider of obstetric services in Western Australia. A purposive sample was drawn from breastfeeding women who used the Snoezelen room during their postpartum stay from March 2006 to March 2007. Saturation was achieved after eleven breastfeeding women were interviewed six weeks post discharge. Data analysis involved the constant comparison method.

Results

Participants entered the room feeling tired and emotional with an unsettled baby and breastfeeding issues aggravated by maternal stress and anxiety. All women indicated they were able to achieve relaxation while in the room and would recommend its use to other breastfeeding mothers. Two key themes revealed how the Snoezelen room facilitated maternal relaxation, which ultimately enhanced the breastfeeding experience. The first theme, "Finding Relaxation for the Breastfeeding Mother" incorporates three subthemes: 'Time out' for mother; Control in own personal space; and a Quiet/calm environment with homelike atmosphere. The second theme, "Enabling Focus on Breastfeeding", occurred after relaxation was achieved and involved four subthemes: Able to get one-on-one attention; Not physically exposed to others; Away from prying, judgemental eyes and Able to safely attempt breastfeeding alone knowing help is nearby.

Conclusion

Insight into how the Snoezelen room promoted relaxation also highlights what contributes to maternal anxiety during breastfeeding experiences in hospital. The findings offer health professionals the opportunity to consider adopting strategies such as a Snoezelen room in their hospital or being innovative in modifying the postpartum setting to promote relaxation for breastfeeding women.     

Pinpointing a selective sweep to the chimpanzee MHC class I region by comparative genomics

Chimpanzees experienced a reduction of the allelic repertoire at the major histocompatibility complex (MHC) class I A and B loci, which may have been caused by a retrovirus belonging to the simian immunodeficiency virus (SIV) family. Extended MHC haplotypes were defined in a pedigreed chimpanzee colony. Comparison of genetic variation at microsatellite markers mapping inside and outside the Mhc region was carried out in humans and chimpanzees to investigate the genomic extent of the repertoire reduction. Multilocus demographic analyses underscored that chimpanzees indeed experienced a selective sweep that mainly targeted the chromosomal segment carrying the Mhc class I region. Probably due to genetic linkage, the sweep also affected other polymorphic loci, mapping in the close vicinity of the Mhc class I region genes. Nevertheless, although the allelic repertoire at particular Mhc class I and II loci appears to be limited, naturally occurring recombination events allowed the establishment of haplotype diversity after the sweep. However, recombination did not have sufficient time to erase the signal of the selective sweep.     

Spatial Variation among Lakes within Landscapes: Ecological Organization along Lake Chains

Although limnologists have long been interested in regional patterns in lake attributes, only recently have they considered lakes connected and organized across the landscape, rather than as spatially independent entities. Here we explore the spatial organization of lake districts through the concept of landscape position, a concept that considers lakes longitudinally along gradients of geomorphology and hydrology. We analyzed long-term chemical and biological data from nine lake chains (lakes in a series connected through surface or groundwater flow) from seven lake districts of diverse hydrologic and geomorphic settings across North America. Spatial patterns in lake variables driven by landscape position were surprisingly common across lake districts and across a wide range of variables. On the other hand, temporal patterns of lake variables, quantified using synchrony, the degree to which pairs of lakes exhibit similar dynamics through time, related to landscape position only for lake chains with lake water residence times that spanned a wide range and were generally long (close to or greater than 1 year). Highest synchrony of lakes within a lake chain occurred when lakes had short water residence times. Our results from both the spatial and temporal analyses suggest that certain features of the landscape position concept are robust enough to span a wide range of seemingly disparate lake types. The strong spatial patterns observed in this analysis, and some unexplained patterns, suggest the need to further study these scales and to continue to view lake ecosystems spatially, longitudinally, and broadly across the landscape.     

Comparison of the pro-oxidative and proinflammatory effects of organic diesel exhaust particle chemicals in bronchial epithelial cells and macrophages

Inhaled diesel exhaust particles (DEP) exert proinflammatory effects in the respiratory tract. This effect is related to the particle content of redox cycling chemicals and is involved in the adjuvant effects of DEP in atopic sensitization. We demonstrate that organic chemicals extracted from DEP induce oxidative stress in normal and transformed bronchial epithelial cells, leading to the expression of heme oxygenase 1, activation of the c-Jun N-terminal kinase cascade, IL-8 production, as well as induction of cytotoxicity. Among these effects, heme oxygenase 1 expression is the most sensitive marker for oxidative stress, while c-Jun N-terminal kinase activation and induction of apoptosis-necrosis require incremental amounts of the organic chemicals and increased levels of oxidative stress. While a macrophage cell line (THP-1) responded in similar fashion, epithelial cells produced more superoxide radicals and were more susceptible to cytotoxic effects than macrophages. Cytotoxicity is the result of mitochondrial damage, which manifests as ultramicroscopic changes in organelle morphology, a decrease in the mitochondrial membrane potential, superoxide production, and ATP depletion. Epithelial cells also differ from macrophages in not being protected by a thiol antioxidant, N-acetylcysteine, which effectively protects macrophages against cytotoxic DEP chemicals. These findings show that epithelial cells exhibit a hierarchical oxidative stress response that differs from that of macrophages by more rapid transition from cytoprotective to cytotoxic responses. Moreover, epithelial cells are not able to convert N-acetylcysteine to cytoprotective glutathione.